In many commercial applications particulate materials may be screened at very high rates of throughput. In the grain industry, for example, screeners handle grain throughputs as large as 40,000 bushels per hour or even more. Because a screen of given type and area will have an optimal operating rate above which it does not screen as efficiently, higher rates generally require larger screen areas. In order to handle a high flow rate while minimizing the floor area of the machine, it has been the practice for many years to provide the needed area among a plurality of screens or "decks" arranged one above another as a stack, and to divide the material to be screened into several fractions for separate screening on the respective screens. After the fines in each fraction have been separated on the respective screen, the product fractions are recombined.
In order to most effectively utilize each screen of such a stack or "bank", it is important to divide the input stream into essentially equal fractions of uniform flow rate, to feed the respective screens equally so that no screen is underfed and none is overfed. At the same time it is important that the fractions be fed onto the respective screens in a manner which rapidly distributes the material over the screen area, so that all of the area will be used at an effective rate.
This invention is aimed at providing a feed splitter or distributor for a multiple deck screener which at any flow rate will more accurately divide the feed stream into separate substantially equal fractions and distribute those fractions onto the respective screens in a manner to use the area of each screen more effectively.